I've been growing over 20 Pulasan trees here in Southwestern India. From what i've observed, Pulasan trees are dioecious that require a male tree for healthy fruit setting. There's fruit set even without the male trees, but there are chances that the fruits can be flat - i.e., not properly developed. Such fruits will have very little flesh with no seeds, and sometimes no flesh at all. So it's better to plant a male tree, say for every 20 or more trees for consistent production of good quality fruits.
And Pulasan is an ultra tropical tree, best suited to equatorial climate, say within the 15nth parallel. It is more shade loving than rambutan.